C++ 尝试将FreeType与CImg一起使用

我使用一些使用FreeType2的代码：

void drawText( FT_Face &face, cimg_library::CImg < unsigned char > &image, const int &heightText, const std::wstring &text, const int &leftTopX, const int &leftTopY, int &width, int &height, unsigned char fontColor[] = NULL, const int separeteGlyphWidth = 1 ) {

    width = 0;
    height = 0;

    FT_Set_Pixel_Sizes( face, 0, heightText );
    FT_GlyphSlot glyphSlot = face->glyph;  

    int shiftX = leftTopX;
    int shiftY = 0;
    for( int numberSymbol = 0; numberSymbol < text.length(); ++numberSymbol ){

        shiftY = leftTopY;

        bool isSpace = false;
        FT_ULong symbol = text[ numberSymbol ]; //FT_ULong symbol = text.at(numberSymbol);
        if (symbol == ' ') {
            symbol = 'a';
            isSpace = true;
        }

        if( FT_Load_Char( face, symbol, FT_LOAD_RENDER ) ) throw "Error, glyph not load!! \n";

        shiftY = heightText - glyphSlot->bitmap.rows;
        if ( shiftY < 0 ) shiftY = 0;

        std::cout << "char: " << (char) text.at( numberSymbol ) << " \tshiftY = " << shiftY << "\t rows = " << glyphSlot->bitmap.rows << "\t extra = " << ( glyphSlot->advance.y >> 6 ) << "\n";

        if ( !isSpace ) drawGlyph( glyphSlot, image, shiftX, shiftY, fontColor );

        shiftX += glyphSlot->bitmap.width + separeteGlyphWidth;

        if( height < shiftY + glyphSlot->bitmap.rows ) height = shiftY + glyphSlot->bitmap.rows;
        width = shiftX;

    }

}


std::string str = "Let me speak from my heart!";
std::wstring wStr( str.begin(), str.end() );

int width, height;
drawText( face, myCImg, 50, wStr, 50, 50, width, height );

void drawText（FT_Face&Face，cimg_library:：cimg&image，const int&heightText，const std:：wstring&text，const int&leftTopX，const int&leftTopY，int&width，int&height，unsigned char fontColor[]=NULL，const int separateglyphwidth=1）{
宽度=0；
高度=0；
设置像素大小（面、0、高度文本）；
FT_GlyphSlot GlyphSlot=面->字形；
int shiftX=leftTopX；
int-shiftY=0；
for（int numberSymbol=0；numberSymbolbitmap.rows；
如果（移位<0）移位=0；
std:：cout metrics.vertAdvance但我不知道如何正确使用它。
快速查看Y偏移的值似乎应该基于
位图\u top
，如果需要像素坐标

所以我建议换一条线

shiftY = heightText - glyphSlot->bitmap.rows;

到

通过查看以以下方式使用这些值的，似乎也证实了这一点：

/* now, draw to our target surface */
my_draw_bitmap( &slot->bitmap,
              pen_x + slot->bitmap_left,
              pen_y - slot->bitmap_top );

/* increment pen position */
pen_x += slot->advance.x >> 6;

只要浏览一下文档，我就会尝试使用
bitmap\u-top
像
shiftY=heightText-glyphSlot->bitmap\u-top；
@PeterT，哈，谢谢你！它真的很有效！：）你可以添加这些信息作为答案-我会接受的。再次感谢你！这真的帮了我的忙！
/* now, draw to our target surface */
my_draw_bitmap( &slot->bitmap,
              pen_x + slot->bitmap_left,
              pen_y - slot->bitmap_top );

/* increment pen position */
pen_x += slot->advance.x >> 6;